Increasing disc drive areal density has resulted in a drastic decrease in head media spacing (HMS). Spacing loss due to variation in fly height has become a significant contributor to the overall HMS losses. This HMS loss can lead to intermittent head/media contact, especially with current sub 15 nanometer fly heights. Intermittent contact may induce vibrations detrimental to the recording system quality and robustness.
Electrodes can be deposited in etched cavities on a slider and can be used to control fly height electrostatically. There are problems with high variations in the etched depth of the cavities that lead to high variations in the spacing between the electrode and the disc. The sensitivity (stroke) of these electrostatic actuators is unpredictable and production yields are low.
An electrostatic actuator for controlling fly height in a disc drive is needed that will avoid unpredictable actuator sensitivity, avoid low production yields and avoid the problems with variations in etched cavity depths.
Embodiments of the present invention provide solutions to these and other problems, and offer other advantages over the prior art.